import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

public class Test02 {
    List<List<List<String>>> res;
    public List<List<List<String>>> solveNQueens(int n){
        List<List<String>> board = new ArrayList<>();
        board.size(1) = n;
        backtrack(board,0);
        return res;
    }

    private void backtrack(List<List<String>> board, int row) {

    }

}
